JPH084928A - Valve - Google Patents

Abstract

PURPOSE:To prevent the occurrence of the dissimilar metal contact corrosion between a threaded cylinder and a piping member by forming the threaded cylinder out of the same metallic material as the piping member, and insulating a valve body and a fixing member through an electric insulating layer and a resin core. CONSTITUTION:A valve 1a is of a gate valve, and provided with sockets 11, 11 on each side, and consists of a valve body 2, a threaded cylinder 3, a resin core 4, and a fixing member 5. A resin lined steel tube is connected to the sockets 11, 11 on each side. The valve body 2 is a casting made of bronze, and female screw holes 21, 21 are provided on each side. The threaded cylinder 3 is made of iron, and a female screw 31 is provided on the inner surface, and the outer circumferential surface is covered with the resin film 6 which is the electric insulating layer. The resin core 4 consists of a cylindrical core body 41 provided opposite to the female screw 31 and a socket 42 to receive the end surface of the threaded cylinder 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve useful for connecting a metal pipe having a natural potential different from that of a metal material forming the valve.

[0002]

2. Description of the Related Art Conventionally, as a water supply pipe, a lining steel pipe having an inner surface lined with a resin so as to prevent rust and red water from being generated inside is used. As a valve provided in the middle of a water supply pipe using such a lining steel pipe, there is a valve as disclosed in JP-A-2-134479.

As shown in FIG. 6, the valve 100 is
The lining steel pipe 103 has the receiving ports 101 on both sides, and the internal thread portion 102 provided on the inner peripheral surface of the receiving port 101 is screwed into the male screw portion 104 provided on the outer peripheral surface of the end portion of the lining steel pipe 103. A cylindrical resin core 105 is provided so as to be connected to the female threaded portion 102, and at the same time when the lining steel pipe 103 is connected, the resin core 105 is connected to the lining steel pipe 1.
The steel pipe portion 106 that is in close contact with the inner peripheral surface of the pipe 03 and is exposed at the pipe end of the lining steel pipe 103 is exposed to hot water or water flowing in the pipe so that rust does not occur.

[0004]

By the way, a hot water supply line such as a water heater for heating and supplying water supplied from a water supply pipe is connected using a valve made of a corrosion-resistant copper alloy or stainless steel. Often. However, even if the valve 100 as described above is used and the steel pipe portion 106 at the pipe end of the lining steel pipe 103 is not exposed to the hot water or water flowing in the pipe by the resin core 105, the copper alloy forming the valve Since copper and steel have different natural potentials from each other, when used for a long period of time, potential difference corrosion occurs due to the difference in natural potential at the screw connection portion between the steel pipe 103 and the valve 100, and the screws disappear and the steel pipe 103 disappears. There is a problem that is missing.

In order to solve such a problem, a method of interposing an insulating joint between the valve and the steel pipe has been implemented. In this method, the insulating joint must be prepared separately. Since the extra step of connecting the valve and the insulating joint is required, the workability is very poor. In view of the above circumstances, the present invention provides a valve capable of completely preventing contact corrosion of dissimilar metals even when connecting dissimilar metal pipes, and having a simple manufacturing process and a reduced manufacturing cost. Is intended.

[0006]

In order to achieve such an object, in an insulating joint according to the present invention, in a valve having a metal valve body and two receiving ports, at least the valve body and the natural potential are The receiving end on the side to which the pipe material made of a different metal is connected has a female screw on the inner peripheral surface to which a male screw provided on the tip outer peripheral surface of the pipe material connected with the same material as the connected pipe material is screwed A resin having a threaded cylinder provided with the core body and a tip end of a pipe member connected to the core member, the outer peripheral surface of which is watertightly adhered to the inner peripheral surface of the pipe member, and a receiving portion of the end surface of the screw cylinder. The core and the screw cylinder are surrounded from the outside in a state of being insulated from the screw cylinder through the electric insulation layer, and the male screw provided at one end is screwed into the female screw hole provided on one side of the valve body, and the other. The screw cylinder is a locking part that protrudes inward from the edge. It has a configuration which is formed from a metal securing member to lock the end.

In the above construction, the synthetic resin constituting the resin core is not particularly limited, but for example, polyvinyl chloride, polyethylene, polybutene, polypropylene, ABS resin, polyvinylidene fluoride (PVDF),
Polyamide (nylon), polyether ether ketone (PEEK), polyphenylene sulfide (PPS),
Cross-linked polyethylene and the like can be mentioned, and a composite material of these resins and glass fiber, carbon fiber or the like may be used.

The metal constituting the valve body is not particularly limited, but examples thereof include iron, copper, gun metal, bronze and the like.
Ball valves, gate valves,
Check valves, strainers, pressure reducing valves, etc. may be mentioned. The electrically insulating layer can be formed by coating the outer peripheral surface of the screw cylinder with a resin or covering the outer peripheral surface of the screw cylinder with a resin film. Examples of the resin as the electric insulation layer include polyamide (nylon) and tetrafluoroethylene resin (fluorine resin).

[0009]

According to the above construction, when the pipe member made of a metal different from that of the valve body is connected to the receiving port formed of the screw cylinder, the resin core and the fixing member, the screw cylinder has the same metal material as the pipe member. And is insulated from the valve body and the fixing member via the electric insulating layer and the resin core, there is no problem of corrosion of dissimilar metal contact between the screw cylinder and the pipe material.

Further, when the pipe material is a lining steel pipe, the resin core provided on the adapter by the connection adheres to the inner surface of the lining steel pipe in a watertight manner, so that the steel pipe portion exposed at the pipe end of the lining steel pipe flows in the pipe. Insulated from water and water.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings showing the embodiments thereof. FIG. 1 shows a first embodiment of a valve according to the present invention. As shown in FIG. 1, this valve 1a is a gate valve, which is provided with receiving ports 11, 11 on both sides, and is composed of a valve body 2, a screw cylinder 3, a resin core 4, and a fixing member (cap nut) 5. The resin-lined steel pipe is connected to the receiving ports 11, 11 on both sides.

The valve body 2 is a casting made of bronze,
Female screw holes 21 and 21 are provided on both sides. The screw cylinder 3
It is made of iron and has an internal thread 31 provided on its inner surface and an outer peripheral surface covered with a resin film 6 serving as an electric insulating layer. The resin core 4 is composed of a tubular core body 41 provided facing the female screw 31 and a receiving portion (flange portion) 42 that receives the end surface of the screw barrel 3.

The screw cylinder 3 is installed in the screw hole 21 in a state where the end face is received by the receiving portion 42 of the resin core 4. The core body 41 has an outer diameter substantially the same as the inner diameter of the resin-lined steel pipe to be connected. The fixing member 5 has a tubular shape made of cast bronze, and is integrated with the valve body 2 by screwing a male screw 51 provided on one side into the female screw hole 21.

Further, the fixing member 5 is integrated with the valve main body 2 and at the same time surrounds the screw cylinder 3 over the resin film 6 and extends inward from the peripheral edge of the other side.
The screw cylinder 3 and the resin core 4 are fixedly integrated with the valve body 2 by locking the end surface of the screw cylinder 3. In FIG. 1, 7 is an O-ring for connecting the valve body 2 and the resin core 4 in a watertight manner, and 8 is an O-ring for connecting between the resin core 4 and the screw cylinder 3 in a watertight manner. is there.

Since the valve 1a is configured as described above, even if a lining steel pipe is connected to the receiving port 11 as a piping material, the valve body 2 and the steel pipe portion of the lining steel pipe do not come into direct contact with each other. At the same time as the connection, the core body 41
Fits inside the lining steel pipe, and the outer peripheral surface of the core body 41 adheres to the inner peripheral surface of the lining steel pipe in a watertight manner, so that the steel pipe portion exposed at the pipe end of the lining steel pipe directly contacts hot water or water flowing in the pipe. Not exposed.

That is, the steel pipe portion of the lining steel pipe will not cause potential difference corrosion due to contact with different metals, and the steel pipe portion will not be corroded by being exposed to hot water or water. Therefore, red water is not generated in the pipe. Of course, a pipe material other than the lining steel pipe can be connected to the valve 1a.

FIG. 2 shows a second embodiment of the valve according to the present invention. As shown in FIG. 2, this valve 1b
Has one receptacle 11 similar to the valve 1a of the first embodiment, and the other receptacle 12 has a bronze adapter 9
It is the same as the first embodiment except that it is formed by screwing the male screw 91 of the above into the other female screw hole 21.

That is, in the valve 1b of this embodiment, a resin-lined steel pipe can be connected to one receiving port 11 and a bronze pipe material can be connected to the other receiving port 12.
In FIG. 2, reference numeral 92 is a female screw 92. The valve according to the present invention is not limited to the above embodiment. For example, in the above embodiment, in order to maintain the watertightness of the connecting portion between the valve body 2 and the adapter 3, one O ring 7 or 8 is used, but as shown in FIG.
The two O-rings 7, 7 (8, 8) may be doubled, or the N-ring 71 may be used instead of the O-ring 7 (8) as shown in FIG. 4, or as shown in FIG. Alternatively, the W ring 72 may be used.

When the valve is a ball valve, the ball valve and the resin core may be brought into direct contact with each other so that the core also serves as a seal ring.

[0020]

Since the valve according to the present invention is configured as described above, the valve body and the piping material do not come into direct contact with each other even when the piping material having a natural potential different from that of the valve body is connected. Therefore, the piping material does not cause potential difference corrosion due to contact with different metals. Moreover, when the pipe material is a lining steel pipe, the outer peripheral surface of the core is watertightly adhered to the inner peripheral surface of the lining steel pipe, so the steel pipe part exposed at the pipe end of the lining steel pipe is directly exposed to hot water or water flowing in the pipe. Never be done. It cannot be said that the steel pipe part is exposed to hot water or water and corrodes.

Further, a resin core is provided in the female screw hole of the valve body,
It is easy to manufacture because it can be assembled by inserting the screw cylinder, arranging the fixing member so as to surround the resin core and the screw cylinder from the outside, and screwing this fixing member into the female screw hole of the valve body. The cost can also be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a valve according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the valve according to the present invention.

FIG. 3 is a cross-sectional view showing another example of the seal portion between the valve body and the resin core.

FIG. 4 is a cross-sectional view showing a second another example of the seal portion between the valve body and the resin core.

FIG. 5 is a sectional view showing a third another example of the seal portion between the valve body and the resin core.

FIG. 6 is a cross-sectional view of a known valve.

[Explanation of symbols]

 1a valve 1b valve 2 valve body 3 screw cylinder 4 resin core 5 fixing member 6 resin film (electrical insulating layer) 11 receptacle 12 receptacle 21 female screw hole 31 female screw 41 core body 42 receptacle 51 male screw 52 locking portion

Claims (1)

[Claims] 1. In a valve having a metal valve body and two receiving ports, at least the receiving port on the side to which the metallic piping material having a natural potential different from that of the valve body is connected is connected to the piping material. Fit the inside of the tip end of the pipe material to which the core body is connected, and the threaded cylinder with the female thread on the inner peripheral surface that the male screw provided on the outer peripheral surface of the tip end of the pipe material connected with the same material The outer peripheral surface of the screw tube adheres to the inner peripheral surface of the pipe material in a watertight manner, and the screw tube from the outside in a state of being insulated from the screw tube through the resin core having the receiving portion of the end surface of the screw tube and the electric insulation layer. A metal that surrounds the male screw provided at one end and is screwed into a female screw hole provided at one side of the valve body, and the end portion of the screw cylinder is locked by a locking portion projecting inward from the peripheral edge of the other end. A valve formed of a fixed member made of metal.